The effect of early experience on MHC-based mate preferences in two B10.W strains of mice (Mus domesticus).

Previous experiments have demonstrated that mice of some strains show mate preferences that are based on genes of the major histocompatibility complex (MHC), and rearing environment appears to influence these preferences. This experiment investigated if fostering affected MHC-based mate preferences in two additional strains of mice for which it was known that females exhibited MHC-dissimilar preferences. Pups were exchanged between families of B10.GAA37 and B10.CHR51 mouse strains, which differed genetically from one another only at MHC loci. At sexual maturity foster mice were given a choice of two opposite-sex mice of either the foster-family or the foster-mouse MHC type. Preference was based on time spent with each stimulus mouse, the first ejaculation, or the first mount with a stimulus mouse. Although the results were not significant in general, females of the B10.GAA37 strain were mounted first significantly more often by non-foster-family males; first mounts predicted ejaculation preference. The results suggest that rearing environment did affect MHC-based preferences in females of this strain, although learning of self-MHC cues and use of non-MHC cues for mate choice may also occur. These results are compared to those of previous experiments.